Self-assembled monolayer for electrode modification and device comprising such self-assembled monolayer

ABSTRACT

The present application relates to a self-assembled monolayer suitable for the modification of electrodes comprised in electronic devices as well as to such electronic devices. The present application also relates to a method for depositing such self-assembled monolayer onto an electrode as well as to the manufacturing of the corresponding devices.

TECHNICAL FIELD

The present application relates to a self-assembled monolayer suitablefor the modification of electrodes comprised in electronic devices aswell as to such electronic devices. The present application also relatesto a method for depositing such self-assembled monolayer onto anelectrode as well as to the manufacturing of the corresponding devices.

BACKGROUND

Organic electronic materials have established their presence in a widerange of electronic devices, such as organic photodetectors (OPD),organic photovoltaic cells (OPV), organic light emitting diodes (OLEDs)and organic field effect transistors (OFETs), to name a few only.Because they may be deposited onto an underlying substrate by solutionprocessing, organic materials hold the promise of allowing forsimplified and highly flexible production, potentially also leading toreduced manufacturing costs.

In order to obtain an efficient organic electronic device, the workfunction of the electrode materials has to match the energy level of thehighest occupied molecular orbital (HOMO) for a p-type organicsemiconducting material and of the lowest unoccupied molecular orbital(LUMO) for an n-type organic semiconducting material. Therefore, for ap-type organic electronic device gold, palladium and platinum aresuitable electrode materials. Alternatively, silver electrodes have beenused in combination with self-assembled monolayers, wherein theself-assembled monolayer brings the work function of the electrode to alevel suitable for a p-type organic electronic device.

An overview of the work function of the chemical elements is given inHerbert B. Michaelson, Journal of Applied Physics 48, 4729 (1977); doi:10.1063/1.323539. However, on the downside noble metal electrodes addsignificant cost to the organic electronic device and there is thereforean interest in using lower cost metals as electrode materials.

Copper may, for example, be considered as a potential alternativeelectrode material because of its good conductivity, relatively low costand relative ease to use in manufacturing processes. In addition, copperis already widely used in the semiconductor industry.

However, copper is chemically quite reactive and also requires surfacemodification in order to match the work function of the copper electrodeto the respective organic semiconducting material. Such surfacemodification may, for example, be done by plating the copper surfacewith silver. Unfortunately, this frequently leads to the formation ofsilver dendrites, consequently rendering the so-produced electronicdevices less efficient or even completely useless.

As alternative electrode material molybdenum may also be used, forexample, in combination with a self-assembled monolayer thereon formedby the deposition of octadecyltrichlorosilane andphenethyltrichlorosilane, as disclosed by Dong-Jin Yun and Shi-Woo Rheein Journal of the Electrochemical Society 155(6) H357-H362 (2008).

Frequently, in organic electronic devices metal oxide electrodes, suchas for example indium tin oxide (ITO) electrodes, are used. While goodresults have been achieved, it seems that these electrodes need to befurther modified so as to render their work function better suitable fora p-type organic electronic device.

There is therefore a need in the industry to overcome the drawbacks ofthese electrodes.

Hence, it is an object of the present application to provide anelectrode, which is suitable for use in an organic electronic device,preferably at reduced cost.

It is also an object of the present application to provide for anelectrode, the work function of which can be adapted to the respectiveorganic semiconducting materials used in the organic electronic device.

In addition, it is an object of the present application to provide for acompound and/or a method whereby the work function of a metal oxideelectrode can be adapted to the requirements of a p-type organicelectronic device.

Further, it is an object to provide for an organic electronic devicehaving good, preferably improved, performance, for example electronicperformance.

Additionally, it is an object of the present application to provide fora production process for such electrode and such organic electronicdevice.

SUMMARY

The present inventors have now surprisingly found that the above objectsmay be attained either individually or in any combination by the organicelectronic device and its production method as disclosed herein.

The present application therefore provides for an organic electronicdevice comprising an electrode, a self-assembled monolayer on saidelectrode and an organic semiconducting layer on said self-assembledmonolayer, wherein said self-assembled monolayer is formed by depositingthe reaction product of a compound of the following formula (I)

R¹—SiX₃  (I)

and an alcohol of formula R²—OH onto said electrode,with

-   R¹ being at each occurrence independently alkyl having from 1 to 10    carbon atoms, said alkyl being substituted with at least one    electron-withdrawing group R^(A), or aryl having from 6 to 30    aromatic carbon ring atoms, said aryl being substituted with at    least one electron-withdrawing group;-   R² being an alkyl group having from 1 to 10 carbon atoms; and-   X being at each occurrence independently halogen or alkoxy having    from 1 to 10 carbon atoms.

Further, the present application also provides for a method of producingthe organic electronic device of any one or more of claims 1 to 12, saidmethod comprising the steps of

-   (a) providing an electrode, optionally on a substrate;-   (b) depositing onto said electrode a formulation comprising a    compound of formula (I)

R¹—SiX₃  (I)

-   -   and an alcohol of formula R²—OH,    -   with    -   R¹ being at each occurrence independently alkyl having from 1 to        10 carbon atoms, said alkyl being substituted with at least one        electron-withdrawing group R^(A), or aryl having from 6 to 30        aromatic carbon ring atoms, said aryl being substituted with at        least one electron-withdrawing group R^(A);    -   R² being an alkyl group having from 1 to 10 carbon atoms; and    -   X being at each occurrence independently halogen or alkoxy        having from 1 to 10 carbon atoms,    -   to obtain a self-assembled monolayer; and

-   (c) depositing onto said self-assembled monolayer an organic    semiconducting material to obtain an organic semiconducting layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic representation of an exemplary top gate OFET inaccordance with the present application.

FIG. 2 shows a schematic representation of an exemplary bottom gate OFETin accordance with the present application.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “organic electronic device” refers to anelectronic device comprising an organic semiconducting layer, i.e. asemiconducting layer comprising at least 50 wt % (e.g. 60 wt % or 70 wt% or 80 wt % or 90 wt % or 95 wt % or 97 wt % or 99.0 wt % or 99.5 wt %or 99.7 wt % or 99.9 wt %), with wt % relative to the total weight ofsaid semiconducting layer, and preferably consists of one or moreorganic semiconducting material.

As used herein, the terms “consist of” and “consisting of” do notexclude the presence of impurities, which may normally be present, forexample but in no way limited to, impurities resulting from thesynthesis of a compound (e.g. an organic semiconducting material) or—incase of metals—trace metals.

For the purposes of the present application, an asterisk “*” is used todenote a linkage to an adjacent unit or group, including for example, incase of a polymer, to an adjacent repeating unit or any other group. Insome instances, where specifically identified as such, the asterisk “*”may also denote a mono-valent chemical group.

In general terms the present application relates to an organicelectronic device. Said organic electronic device comprises anelectrode, a self-assembled monolayer and an organic semiconductinglayer, wherein the self-assembled monolayer is (or is formed) on theelectrode, and wherein the organic semiconducting layer is on (or isdeposited onto) the self-assembled monolayer. Expressed differently, theorganic electronic device comprises an electrode, a self-assembledmonolayer and an organic semiconducting layer, with the self-assembledmonolayer between the electrode and the organic semiconducting layer.

The electrode comprises a metal or an electrically conductive metaloxide or a blend thereof, preferably in at least 50 wt % (for example inat least 60 wt % or 70 wt % or 80 wt % or 90 wt % or 95 wt % or 97 wt %or 99.0 wt % or 99.5 wt % or 99.7 wt % or 99 wt %), with wt % relativeto the total weight of said electrode, and most preferably consists ofthe metal or the electrically conductive metal oxide or a blend thereof.

It is noted that the term “metal” as used herein also includes thepossibility of a blend of two or more metals. It is also noted that theterm “electrically conductive metal oxide” as used herein also includesthe possibility of a blend of two or more metal oxides and/or thepossibility of mixed metal oxides.

Said metal is not particularly limited. Metals generally suitable may,for example, be selected from the group consisting of chromium,molybdenum, tungsten, cobalt, rhodium, iridium, nickel, palladium,platinum, gold, silver, and any blend of any of these, with chromium,molybdenum and tungsten being preferred, and molybdenum being mostpreferred.

Said metal oxide is not particularly limited, it is neverthelesspreferred that the electrically conductive metal oxide is selected fromthe group consisting of indium tin oxide (ITO), molybdenum oxide, tinoxide, and any blend of any of these.

The self-assembled monolayer essentially covers the electrode. In thiscontext the term “essentially covers” is used to denote that—dependingupon the architecture of the respective organic electronic device—theself-assembled monolayer covers the electrode in such a way thatpreferably no part of the electrode is in direct physical contact withthe organic semiconducting layer; or that the self-assembled monolayercovers the entire surface of the electrode, preferably the entiresurface of the electrode facing the organic semiconducting layer; orthat the self-assembled monolayer covers the part of the surface of theelectrode that is active in the change transfer.

The self-assembled monolayer is formed by depositing a formulationcomprising a compound of the following formula (I)

R¹—SiX₃  (I)

and an alcohol of formula R²—OH, with R¹, R² and X as defined herein,onto said electrode.

R² is an alkyl group having from 1 to 10 carbon atoms. Preferably, R² isan alkyl group having from 1 to 5 carbon atoms. Examples of suchpreferred groups R² may be selected from the group consisting of methyl,ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl andn-pentyl. It is most preferred that R² is iso-propyl.

Without wishing to be bound by theory it is believed that the compoundof formula (I) reacts with the alcohol of formula R²—OH to formcompounds of the following formula (I-a) to (I-c)

R¹—SiX₂(OR²)  (I-a)

R¹—SiX(OR²)₂  (I-b)

R¹—Si(OR²)₃  (I-c)

of which formula (I-c) is, without wishing to be bound by theory,considered the majority compound, possibly even the sole compound.

Thus, consequently, without wishing to be bound by theory, it isbelieved that the self-assembled monolayer may actually be formed bydepositing the reaction product of the compound of formula (I) and thealcohol of formula R²—OH, for example by depositing any one or more ofcompounds (I-a) to (I-c), preferably of compound (I-c) predominantly oreven solely.

X is at each occurrence independently halogen, preferably Cl, or analkoxy group having from 1 to 10 carbon atoms. Preferably the alkoxygroup is —O—C_(a)H_(2a+1) with a being an integer of at least 1 and ofat most 10, preferably of at least 1 and of at most 5. Examples ofpreferred alkoxy groups may be selected from the group consisting of—O—CH₃, —O—CH₂—CH₃, —O—(CH₂)₂—CH₃, —O—CH(CH₃)₂, —O—(CH₂)₃—CH₃,—O—C(CH₃), and —O—CH₂—CH(CH₃)₂. A particularly preferred alkoxy group is—O—CH(CH₃)₂.

R¹ is at each occurrence independently alkyl having from 1 to 10 carbonatoms, said alkyl being substituted with at least oneelectron-withdrawing group R^(A), or aryl having from 6 to 30 aromaticcarbon ring atoms, said aryl being substituted with at least oneelectron-withdrawing group R^(A).

Preferably R¹ is at each occurrence independently a group of any one ofthe following formulae (II-a) or (II-b)

wherein

-   b is at each occurrence independently an integer of at least 1 and    of at most 10, preferably of at most 5;-   c is at each occurrence an integer of at least 1 and at most 2b+1,    and preferably is 2b+1;-   d is at each occurrence an integer of at least 0 and at most 2b, and    preferably is 0;    with the provision that the sum of c and d is 2b+1, i.e. c+d=2b+1;-   e is at each occurrence independently an integer of at least 1 and    of at most 5, and preferably is 5;    and R^(A) is an electron-withdrawing group as defined herein.

R^(A) is an electron withdrawing group. Preferably R^(A) is at eachoccurrence independently selected from the group consisting of —NO₂,—CN, —F, —Cl, —Br, —I, —OAr², —OR³, —COR³, —SH, —SR³, —OH, —C═CR³,—CH═CR³ ₂, and alkyl having from 1 to 10 carbon atoms, wherein one ormore, preferably all, hydrogen atoms are replaced by F, with Ar² and R³as defined herein. More preferably R^(A) is at each occurrenceindependently selected from the group consisting of —CN, —F, —Cl, —Br,—I, —OR³, and alkyl having from 1 to 10 carbon atoms, wherein one ormore, preferably all, hydrogen atoms are replaced by F, with R³ asdefined herein. Even more preferably R^(A) is at each occurrenceindependently selected from the group consisting of —F, —OR³, and alkylhaving from 1 to 10 carbon atoms, wherein one or more, preferably all,hydrogen atoms are replaced by F, with R³ as defined herein. Mostpreferably R^(A) is F.

Ar² is an aryl having from 6 to 30 carbon atoms, preferably having from6 to 20 carbon atoms, and most preferably is phenyl. Preferably Ar² issubstituted with one or more substituent selected from the groupconsisting of —CN, —F, —Cl, —Br, —I, —OR³, and alkyl having from 1 to10, preferably from 1 to 5, carbon atoms, wherein one or more,preferably all, hydrogen atoms are replaced by F, with R³ as definedherein.

R³ is an alkyl having from 1 to 10, preferably from 1 to 5, carbonatoms, or alkyl having from 1 to 10, preferably from 1 to 5, carbonatoms, wherein one or more, preferably all, hydrogen atoms are replacedby F.

Preferred examples of alkyl suitable as R³ may be selected from thegroup consisting of methyl, ethyl, n-propyl, iso-propyl, n-butyl,iso-butyl, tert-butyl and n-pentyl. Preferred examples of fluorinatedalkyl (i.e. alkyl wherein one or more, preferably all, hydrogen atomsare replaced by F) suitable as R³ may be selected from the groupconsisting of —CF₃, —C₂F₅, -n-C₃F₇ (i.e. n-propyl), and -n-C₄F₉ (i.e.n-butyl).

Preferred examples of the compound of formula (I) may be selected fromthe group consisting of the following formulae (I-1) to (I-11)

with X as defined herein, and e being an integer of at least 1 and atmost 10 (for example 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10).

Without wishing to be bound by theory it is believed that the depositionof a compound of formula (I) onto the electrode will result in theformation of one or more —Si—O-M- bonds (with M being a metal atomcomprised in the electrode).

Preferably the self-assembled monolayers of the present invention mayhave a thickness (measured perpendicular to the surface of such layer)from 1 to 10, more preferably from 1 to 5, even more preferably from 1to 3, and still even more preferably from 1 to 2 molecular layers. Mostpreferably said thickness is about one molecular layer.

The organic semiconducting material is not particularly limited. Anyorganic semiconducting material may be used, such as for exampleso-called “small molecules” or polymers. The term “small molecules”refers to organic semiconducting compounds that generally have amolecular weight of at most 1000 g mol⁻¹, preferably of at most 500 gmol⁻¹.

The organic semiconducting material can either be an n-type or p-typesemiconducting material. Preferably, said organic semiconductingmaterial has a field effect transistor mobility of at least 1·10⁻⁵ cm²V⁻¹ s⁻¹.

Preferably the organic semiconducting layer is solid. Preferably thesemiconducting layer comprises, and preferably consists of, one or more,preferably one, organic semiconducting material. Preferably, saidsemiconducting material has a transistor mobility of at least 1·10⁻⁵ cm²V⁻¹ s⁻¹ and/or the energy level of the highest occupied molecularorbital (HOMO) of the semiconducting material is lower than the lower ofthe Fermi energy levels of the first and second electrode materials.

The semiconducting layer preferably has a thickness of at least 5 nm,more preferably of at least 10 nm, and of at most 20 μm, more preferablyof at most 15 μm and most preferably of at most 10 μm.

The organic semiconducting material is preferably selected from thegroup consisting of monomeric compounds (also referred to as “smallmolecule”), oligomers, polymers or blends of any of these, for example,including but not limited to blends of one or more monomeric compounds,one or more oligomers or one or more polymers. More preferably theorganic semiconducting material is a polymer or a blend of polymers.Most preferably the organic semiconducting material is a polymer.

The type of organic semiconducting material is not particularly limited.In general the organic semiconducting material comprises a conjugatedsystem. The term “conjugated system” is herein used to denote amolecular entity or a part of a molecular entity, the structure of whichmay be represented as a system of alternating single and multiple bonds(see also International Union of Pure and Applied Chemistry, Compendiumof Chemical Terminology, Gold Book, Version 2.3.3, 2014-02-24, pages322-323).

An organic semiconducting material suited for use herein may, forexample, be represented by the following formula (V)

wherein monomeric unit M and m are as defined herein. At each occurrenceM may be selected independently.

With regards to formula (V) m may be any integer from 1 to 100,000. Fora monomer or monomeric unit m is 1. For an oligomer m is at least 2 andat most 10. For a polymer m is at least 11.

Preferably, the organic semiconducting material comprises one or morearomatic units. Expressed differently, with regards to formula (V), Mmay be an aromatic unit. Such aromatic units preferably comprise two ormore, more preferably three or more aromatic rings. Such aromatic ringsmay, for example, at each occurrence independently be selected from thegroup consisting of 5-, 6-, 7- and 8-membered aromatic rings, with 5-and 6-membered rings being particularly preferred.

These aromatic rings comprised in the organic semiconducting materialoptionally comprise one or more heteroatoms selected from Se, Te, P, Si,B, As, N, O or S, preferably from Si, N, O or S. Further, these aromaticrings may optionally be substituted with alkyl, alkoxy, polyalkoxy,thioalkyl, acyl, aryl or substituted aryl groups, halogen, with fluorinebeing the preferred halogen, cyano, nitro or an optionally substitutedsecondary or tertiary alkylamine or arylamine represented by —N(R′)(R″),where R′ and R″ are each independently H, an optionally substitutedalkyl or an optionally substituted aryl, alkoxy or polyalkoxy groups aretypically employed. Further, where R′ and R″ is alkyl or aryl these maybe optionally fluorinated.

The aforementioned aromatic rings can be fused rings or linked to eachother by a conjugated linking group such as —C(T₁)=C(T₂)-, —C≡C—,—N(R′″)—, —N═N—, (R′″)═N—, —N═C(R′″)—, where T₁ and T₂ eachindependently represent H, Cl, F, —C≡N or loweralkyl groups such as C₁₄alkyl groups; R′″ represents H, optionally substituted alkyl oroptionally substituted aryl. Further, where R′″ is alkyl or aryl, it maybe optionally fluorinated.

Further preferred organic semiconducting materials may be polymers orcopolymers wherein the monomeric units M of formula (V) may at eachoccurrence be independently selected from the group consisting offormulae (A1) to (A83) and (D1) to (D142)

wherein R¹⁰¹, R¹⁰², R¹⁰³, R¹⁰⁴, R¹⁰⁵, R¹⁰⁶, R¹⁰⁷ and R¹⁰⁸ areindependently of each other selected from the group consisting of H andR^(S) as defined herein.

R^(S) is at each occurrence independently a carbyl group as definedherein and preferably selected from the group consisting of any groupR^(T) as defined herein, hydrocarbyl having from 1 to 40 carbon atomswherein the hydrocarbyl may be further substituted with one or moregroups R^(T), and hydrocarbyl having from 1 to 40 carbon atomscomprising one or more heteroatoms selected from the group consisting ofN, O, S, P, Si, Se, As, Te or Ge, with N, O and S being preferredheteroatoms, wherein the hydrocarbyl may be further substituted with oneor more groups R^(T).

Preferred examples of hydrocarbyl suitable as R^(S) may at eachoccurrence be independently selected from phenyl, phenyl substitutedwith one or more groups R^(T), alkyl and alkyl substituted with one ormore groups R^(T), wherein the alkyl has at least 1, preferably at least5 and has at most 40, more preferably at most 30 or 25 or 20, even morepreferably at most 15 and most preferably at most 12 carbon atoms. It isnoted that for example alkyl suitable as R^(S) also includes fluorinatedalkyl, i.e. alkyl wherein one or more hydrogen is replaced by fluorine,and perfluorinated alkyl, i.e. alkyl wherein all of the hydrogen arereplaced by fluorine.

R^(T) is at each occurrence independently selected from the groupconsisting of F, Br, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(O)NR⁰R⁰⁰,—C(O)X⁰, —C(O)R⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —SO₃H, —SO₂R⁰, —OH, —OR⁰,—NO₂, —SF₅ and —SiR⁰R⁰⁰R⁰⁰⁰. Preferred R^(T) are selected from the groupconsisting of F, Br, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(O)NR⁰R⁰⁰,—C(O)X⁰, —C(O)R⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —OH, —OR⁰ and —SiR⁰R⁰⁰R⁰⁰⁰.Most preferred R^(T) is F.

R⁰, R⁰⁰ and R⁰⁰⁰ are at each occurrence independently of each otherselected from the group consisting of H, F and hydrocarbyl having from 1to 40 carbon atoms. Said hydrocarbyl preferably has at least 5 carbonatoms. Said hydrocarbyl preferably has at most 30, more preferably atmost 25 or 20, even more preferably at most 20, and most preferably atmost 12 carbon atoms. Preferably, R⁰, R⁰⁰ and R⁰⁰⁰ are at eachoccurrence independently of each other selected from the groupconsisting of H, F, alkyl, fluorinated alkyl, alkenyl, alkynyl, phenyland fluorinated phenyl. More preferably, R⁰, R⁰⁰ and R⁰⁰⁰ are at eachoccurrence independently of each other selected from the groupconsisting of H, F, alkyl, fluorinated, preferably perfluorinated,alkyl, phenyl and fluorinated, preferably perfluorinated, phenyl.

It is noted that for example alkyl suitable as R⁰, R⁰⁰ and R⁰⁰⁰ alsoincludes perfluorinated alkyl, i.e. alkyl wherein all of the hydrogenare replaced by fluorine. Examples of suitable alkyls may be selectedfrom the group consisting of methyl, ethyl, n-propyl, iso-propyl,n-butyl, iso-butyl, tert-butyl (or “t-butyl”), pentyl, hexyl, heptyl,octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl,hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl (—C₂₀H₄₁).

X⁰ is halogen. Preferably X⁰ is selected from the group consisting of F,Cl and Br.

A hydrocarbyl group comprising a chain of 3 or more carbon atoms andheteroatoms combined may be straight chain, branched and/or cyclic,including spiro and/or fused rings.

Hydrocarbyl suitable as R^(S), R⁰, R⁰⁰ and/or R⁰⁰⁰ may be saturated orunsaturated. Examples of saturated hydrocarbyl include alkyl. Examplesof unsaturated hydrocarbyl may be selected from the group consisting ofalkenyl (including acyclic and cyclic alkenyl), alkynyl, allyl,alkyldienyl, polyenyl, aryl and heteroaryl.

Preferred hydrocarbyl suitable as R^(S), R⁰, R⁰⁰ and/or R⁰⁰⁰ includehydrocarbyl comprising one or more heteroatoms and may for example beselected from the group consisting of alkoxy, alkylcarbonyl,alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy, alkylaryloxy,arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy.

Preferred examples of aryl and heteroaryl comprise mono-, bi- ortricyclic aromatic or heteroaromatic groups that may also comprisecondensed rings.

Especially preferred aryl and heteroaryl groups may be selected from thegroup consisting of phenyl, phenyl wherein one or more CH groups arereplaced by N, naphthalene, fluorene, thiophene, pyrrole, preferablyN-pyrrole, furan, pyridine, preferably 2- or 3-pyridine, pyrimidine,pyridazine, pyrazine, triazole, tetrazole, pyrazole, imidazole,isothiazole, thiazole, thiadiazole, isoxazole, oxazole, oxadiazole,thiophene, preferably 2-thiophene, selenophene, preferably2-selenophene, thieno[3,2-b]thiophene, thieno[2,3-b]thiophene,dithienothiophene, furo[3,2-b]furan, furo[2,3-b]furan,seleno[3,2-b]selenophene, seleno[2,3-b]selenophene,thieno[3,2-b]selenophene, thieno[3,2-b]furan, indole, isoindole,benzo[b]furan, benzo[b]thiophene, benzo[1,2-b;4,5-b′]dithiophene,benzo[2,1-b;3,4-b′]dithiophene, quinole, 2-methylquinole, isoquinole,quinoxaline, quinazoline, benzotriazole, benzimidazole, benzothiazole,benzisothiazole, benzisoxazole, benzoxadiazole, benzoxazole andbenzothiadiazole.

Preferred examples of an alkoxy group, i.e. a corresponding alkyl groupwherein the terminal CH₂ group is replaced by —O—, can be straight-chainor branched, preferably straight-chain (or linear). Suitable examples ofsuch alkoxy group may be selected from the group consisting of methoxy,ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, nonoxy,decoxy, undecoxy, dodecoxy, tridecoxy, tetradecoxy, pentadecoxy,hexadecoxy, heptadecoxy and octadecoxy.

Preferred examples of alkenyl, i.e. a corresponding alkyl wherein twoadjacent CH₂ groups are replaced by —CH═CH— can be straight-chain orbranched. It is preferably straight-chain. Said alkenyl preferably has 2to 10 carbon atoms. Preferred examples of alkenyl may be selected fromthe group consisting of vinyl, prop-1-enyl, or prop-2-enyl, but-1-enyl,but-2-enyl or but-3-enyl, pent-1-enyl, pent-2-enyl, pent-3-enyl orpent-4-enyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, hex-4-enyl orhex-5-enyl, hept-1-enyl, hept-2-enyl, hept-3-enyl, hept-4-enyl,hept-5-enyl or hept-6-enyl, oct-1-enyl, oct-2-enyl, oct-3-enyl,oct-4-enyl, oct-5-enyl, oct-6-enyl or oct-7-enyl, non-1-enyl,non-2-enyl, non-3-enyl, non-4-enyl, non-5-enyl, non-6-enyl, non-7-enyl,non-8-enyl, dec-1-enyl, dec-2-enyl, dec-3-enyl, dec-4-enyl, dec-5-enyl,dec-6-enyl, dec-7-enyl, dec-8-enyl and dec-9-enyl.

Especially preferred alkenyl groups are C₂-C₇-1E-alkenyl,C₄-C₇-3E-alkenyl, C₅-C₇-4-alkenyl, C₆-C₇-5-alkenyl and C₇-6-alkenyl, inparticular C₂-C₇-1E-alkenyl, C₄-C₇-3E-alkenyl and C₅-C₇-4-alkenyl.Examples of particularly preferred alkenyl groups are vinyl,1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl,3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl,4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl and the like. Alkenylgroups having up to 5 C atoms are generally preferred.

Preferred examples of oxaalkyl, i.e. a corresponding alkyl wherein onenon-terminal CH₂ group is replaced by —O—, can be straight-chain orbranched, preferably straight chain. Specific examples of oxaalkyl maybe selected from the group consisting of 2-oxapropyl (=methoxymethyl),2-(=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-, 3-, or4-oxapentyl, 2-, 3-, 4-, or 5-oxahexyl, 2-, 3-, 4-, 5-, or 6-oxaheptyl,2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyland 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.

Preferred examples of carbonyloxy and oxycarbonyl, i.e. a correspondingalkyl wherein one CH₂ group is replaced by —O— and one of the theretoadjacent CH₂ groups is replaced by —C(O)—. may be selected from thegroup consisting of acetyloxy, propionyloxy, butyryloxy, pentanoyloxy,hexanoyloxy, acetyloxymethyl, propionyloxymethyl, butyryloxymethyl,pentanoyloxymethyl, 2-acetyloxyethyl, 2-propionyloxyethyl,2-butyryloxyethyl, 3-acetyloxypropyl, 3-propionyloxypropyl,4-acetyloxybutyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,butoxycarbonyl, pentoxycarbonyl, methoxycarbonylmethyl,ethoxy-carbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl,2-(methoxycarbonyl)ethyl, 2-(ethoxycarbonyl)ethyl,2-(propoxycarbonyl)ethyl, 3-(methoxycarbonyl)propyl,3-(ethoxycarbonyl)propyl, and 4-(methoxycarbonyl)-butyl.

Preferred examples of thioalkyl, i.e where one CH₂ group is replaced by—S—, may be straight-chain or branched, preferably straight-chain.Suitable examples may be selected from the group consisting ofthiomethyl (—SCH₃), 1-thioethyl (—SCH₂CH₃), 1-thiopropyl (—SCH₂CH₂CH₃),1-(thiobutyl), 1-(thiopentyl), 1-(thiohexyl), 1-(thioheptyl),1-(thiooctyl), 1-(thiononyl), 1-(thiodecyl), 1-(thioundecyl) and1-(thiododecyl).

A fluoroalkyl group is preferably perfluoroalkyl C_(i)F_(2i+1), whereini is an integer from 1 to 15, in particular CF₃, C₂F₅, C₃F₇, C₄F₉,C₅F₁₁, C₆F₁₃, C₇F₁₅ or C₈F₁₇, very preferably C₆F₁₃, or partiallyfluorinated alkyl, in particular 1,1-difluoroalkyl, all of which arestraight-chain or branched.

Alkyl, alkoxy, alkenyl, oxaalkyl, thioalkyl, carbonyl and carbonyloxygroups can be achiral or chiral groups. Particularly preferred chiralgroups are 2-butyl (=1-methylpropyl), 2-methylbutyl, 2-methylpentyl,3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, 2-butyloctyl,2-hexyldecyl, 2-octyldodecyl, 7-decylnonadecyl, in particular2-methylbutyl, 2-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy,2-ethyl-hexoxy, 1-methylhexoxy, 2-octyloxy, 2-oxa-3-methylbutyl,3-oxa-4-methyl-pentyl, 4-methylhexyl, 2-butyloctyl, 2-hexyldecyl,2-octyldodecyl, 7-decylnonadecyl, 3,8-dimethyloctyl, 2-hexyl, 2-octyl,2-nonyl, 2-decyl, 2-dodecyl, 6-meth-oxyoctoxy, 6-methyloctoxy,6-methyloctanoyloxy, 5-methylheptyloxy-carbonyl, 2-methylbutyryloxy,3-methylvaleroyloxy, 4-methylhexanoyloxy, 2-chloropropionyloxy,2-chloro-3-methylbutyryloxy, 2-chloro-4-methyl-valeryl-oxy,2-chloro-3-methylvaleryloxy, 2-methyl-3-oxapentyl, 2-methyl-3-oxa-hexyl,1-methoxypropyl-2-oxy, 1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy,1-butoxypropyl-2-oxy, 2-fluorooctyloxy, 2-fluorodecyloxy,1,1,1-trifluoro-2-octyloxy, 1,1,1-trifluoro-2-octyl,2-fluoromethyloctyloxy for example. Most preferred is 2-ethylhexyl.

Preferred achiral branched groups are isopropyl, isobutyl(=methylpropyl), isopentyl (=3-methylbutyl), tert. butyl, isopropoxy,2-methyl-propoxy and 3-methylbutoxy.

In a preferred embodiment, the organyl groups are independently of eachother selected from primary, secondary or tertiary alkyl or alkoxy with1 to 30 C atoms, wherein one or more H atoms are optionally replaced byF, or aryl, aryloxy, heteroaryl or heteroaryloxy that is optionallyalkylated or alkoxylated and has 4 to 30 ring atoms. Very preferredgroups of this type are selected from the group consisting of thefollowing formulae

wherein “ALK” denotes optionally fluorinated, preferably linear, alkylor alkoxy with 1 to 20, preferably 1 to 12 C-atoms, in case of tertiarygroups very preferably 1 to 9 C atoms, and the dashed line denotes thelink to the ring to which these groups are attached. Especiallypreferred among these groups are those wherein all ALK subgroups areidentical.

Further, in some preferred embodiments in accordance with the presentinvention, the organic semiconducting materials are polymers orcopolymers that encompass one or more repeating units, e.g. M in formula(I), selected from thiophene-2,5-diyl, 3-substituted thiophene-2,5-diyl,optionally substituted thieno[2,3-b]thiophene-2,5-diyl, optionallysubstituted thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, or3-substituted selenophene-2,5-diyl.

Preferred examples of organic semiconducting materials comprise one ormore monomeric units selected from the group consisting of formulae (A1)to (A83) and one or more monomeric units selected from the groupconsisting of formulae (D1) to (D142).

Further preferred examples of organic semiconductor materials that canbe used in this invention include compounds, oligomers and derivativesof compounds selected from the group consisting of conjugatedhydrocarbon polymers such as polyacene, polyphenylene, poly(phenylenevinylene), polyfluorene including oligomers of those conjugatedhydrocarbon polymers; condensed aromatic hydrocarbons, such as,tetracene, chrysene, pentacene, pyrene, perylene, coronene, or soluble,substituted derivatives of these; oligomeric para substituted phenylenessuch as p-quaterphenyl (p-4P), p-quinquephenyl (p-5P), p-sexiphenyl(p-6P), or soluble substituted derivatives of these; conjugatedheterocyclic polymers such as poly(3-substituted thiophene),poly(3,4-bisubstituted thiophene), optionally substitutedpolythieno[2,3-b]thiophene, optionally substitutedpolythieno[3,2-b]thiophene, poly(3-substituted selenophene),polybenzothiophene, polyisothianapthene, poly(N-substituted pyrrole),poly(3-substituted pyrrole), poly(3,4-bisubstituted pyrrole), polyfuran,polypyridine, poly-1,3,4-oxadiazoles, polyisothianaphthene,poly(N-substituted aniline), poly(2-substituted aniline),poly(3-substituted aniline), poly(2,3-bisubstituted aniline),polyazulene, polypyrene; pyrazoline compounds; polyselenophene;polybenzofuran; polyindole; polypyridazine; benzidine compounds;stilbene compounds; triazines; substituted metallo- or metal-freeporphines, phthalocyanines, fluorophthalocyanines, naphthalocyanines orfluoronaphthalocyanines; C₆₀ and C₇₀ fullerenes; N,N′-dialkyl,substituted dialkyl, diaryl or substituteddiaryl-1,4,5,8-naphthalenetetracarboxylic diimide and fluoroderivatives; N,N′-dialkyl, substituted dialkyl, diaryl or substituteddiaryl 3,4,9,10-perylenetetracarboxylicdiimide; bathophenanthroline;diphenoquinones; 1,3,4-oxadiazoles;11,11,12,12-tetracyanonaptho-2,6-quinodimethane;a,a′-bis(di-thieno[3,2-b2′,3′-d]thiophene); 2,8-dialkyl, substituteddialkyl, diaryl or substituted diaryl anthradithiophene;2,2′-bisbenzo[1,2-b:4,5-b′]dithiophene. Where a liquid depositiontechnique of the OSC is desired, compounds from the above list andderivatives thereof are limited to those that are soluble in anappropriate solvent or mixture of appropriate solvents.

Other preferred examples of organic semiconducting materials may beselected from the group consisting of substituted oligoacenes, such aspentacene, tetracene or anthracene, or heterocyclic derivatives thereof.Bis(trialkylsilylethynyl) oligoacenes or bis(trialkylsilylethynyl)heteroacenes, as disclosed for example in U.S. Pat. No. 6,690,029 or WO2005/055248 A1 or U.S. Pat. No. 7,385,221, are also useful.

Further preferred organic semiconducting materials are selected from thegroup consisting of small molecules or monomers of the tetra-heteroarylindacenodithiophene-based structural unit as disclosed in WO 2016/015804A1, and polymers or copolymers comprising one or more repeating unitsthereof.

Also preferred organic semiconducting materials may be selected from thegroup of small molecules or monomers or polymers comprising a2,7-(9,9′)spirobifluorene moiety, optionally substituted and preferablysubstituted with amino groups. Such spirobifluorenes are, for example,disclosed in WO 97/39045. Examples of spirobifluorenes suitable for useas monomeric unit M of formula (V) may be selected from the groupconsisting of formulae (VI-1) to (VI-7)

wherein each of the hydrogen atoms may independently of any other be asdefined herein in respect to R¹⁰¹ and each asterisk “*” independentlymay denote a bond to neighboring moiety (for example in a polymer) ormay denote a bond to a group as defined above for R¹⁰¹ (for example in acompound of formula (V-a) or (V-b)). In respect to formulae (VI-1) to(VI-7) preferred substituents, including the ones for “*”, may beselected from the group consisting of alkyl having from 1 to 20 carbonatoms; aryl having from 6 to 20 carbon atoms, said aryl being optionallysubstituted with alkyl or alkoxy having from 1 to 20, preferably 1 to 10carbon atoms; and NR¹¹⁰R¹¹¹ with R¹¹⁰ and R¹¹¹ being independently ofeach other selected from the group consisting of alkyl having from 1 to20 carbon atoms, aryl having from 6 to 20 carbon atoms, said aryl beingoptionally substituted with alkyl or alkoxy having from 1 to 20,preferably 1 to 10 carbon atoms, most preferably R¹¹⁰ and R¹¹¹ beingindependently of each other selected from methyl, ethyl, n-propyl,iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, methoxy, ethoxy,n-propoxy, iso-propoxy n-butoxy, iso-butoxy, tert-butoxy and pentoxy.

In a one aspect the present semiconducting material may, for example, bea small molecule, i.e. a compound comprising one (i.e. m=1) structuralunit of formula (V) and two inert chemical groups R^(a) and R^(b). Sucha small molecule may for example be represented by formula (I-a)

R^(a)-M-R^(b)  (V-a)

wherein M is as defined herein and R^(a) and R^(b) are inert chemicalgroups. Such inert chemical groups R^(a) and R^(b) may independently ofeach other be selected from the group consisting of hydrogen, fluorine,alkyl having from 1 to 10 carbon atoms, alkyl having from 1 to 10 carbonatoms wherein one or more, for example all, hydrogen has been replacedwith fluorine, aromatic ring systems of from 5 to 30 carbon atoms andaromatic ring systems of from 5 to 30 carbon atoms wherein one or morehydrogen atom may independently of any other be replaced by fluorine oralkyl having from 1 to 10 carbon atoms.

Further preferred p-type OSCs are copolymers comprising electronacceptor and electron donor units. Preferred copolymers of thispreferred embodiment are for example copolymers comprising one or morebenzo[1,2-b:4,5-b′]dithiophene-2,5-diyl units that are preferably4,8-disubstituted by one or more groups R as defined above, and furthercomprising one or more aryl or heteroaryl units selected from Group Aand Group B, preferably comprising at least one unit of Group A and atleast one unit of Group B, wherein Group A consists of aryl orheteroaryl groups having electron donor properties and Group B consistsof aryl or heteroaryl groups having electron acceptor properties, andpreferably Group A consists of selenophene-2,5-diyl, thiophene-2,5-diyl,thieno[3,2-b]thiophene-2,5-diyl, thieno[2,3-b]thiophene-2,5-diyl,selenopheno[3,2-b]selenophene-2,5-diyl,selenopheno[2,3-b]selenophene-2,5-diyl,selenopheno[3,2-b]thiophene-2,5-diyl,selenopheno[2,3-b]thiophene-2,5-diyl,benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl, 2,2-dithiophene,2,2-diselenophene, dithieno[3,2-b:2′,3′-d]silole-5,5-diyl,4H-cyclopenta[2,1-b:3,4-b′]dithiophene-2,6-diyl,2,7-di-thien-2-yl-carbazole, 2,7-di-thien-2-yl-fluorene,indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl,benzo[1″,2″:4,5;4″,5″:4′,5′]bis(silolo[3,2-b:3′,2′-b′]thiophene)-2,7-diyl,2,7-di-thien-2-yl-indaceno[1,2-b:5,6-b′]dithiophene,2,7-di-thien-2-yl-benzo[1″,2″:4,5;4″,5″:4′,5′]bis(silolo[3,2-b:3′,2′-b′]thiophene)-2,7-diyl,and 2,7-di-thien-2-yl-phenanthro[1,10,9,8-c,d,e,f,g]carbazole, all ofwhich are optionally substituted by one or more, preferably one or twogroups R as defined above, and

Group B consists of benzo[2,1,3]thiadiazole-4,7-diyl,5,6-dialkyl-benzo[2,1,3]thiadiazole-4,7-diyl,5,6-dialkoxybenzo[2,1,3]thiadiazole-4,7-diyl,benzo[2,1,3]selenadiazole-4,7-diyl,5,6-dialkoxy-benzo[2,1,3]selenadiazole-4,7-diyl,benzo[1,2,5]thiadiazole-4,7,diyl, benzo[1,2,5]selenadiazole-4,7,diyl,benzo[2,1,3]oxadiazole-4,7-diyl,5,6-dialkoxybenzo[2,1,3]oxadiazole-4,7-diyl, 2H-benzotriazole-4,7-diyl,2,3-dicyano-1,4-phenylene, 2,5-dicyano,1,4-phenylene,2,3-difluro-1,4-phenylene, 2,5-difluoro-1,4-phenylene,2,3,5,6-tetrafluoro-1,4-phenylene, 3,4-difluorothiophene-2,5-diyl,thieno[3,4-b]pyrazine-2,5-diyl, quinoxaline-5,8-diyl,thieno[3,4-b]thiophene-4,6-diyl, thieno[3,4-b]thiophene-6,4-diyl, and3,6-pyrrolo[3,4-c]pyrrole-1,4-dione, all of which are optionallysubstituted by one or more, preferably one or two groups R as definedabove.

In other preferred embodiments of the present invention, the OSCmaterials are substituted oligoacenes such as pentacene, tetracene oranthracene, or heterocyclic derivatives thereof.Bis(trialkylsilylethynyl) oligoacenes or bis(trialkylsilylethynyl)heteroacenes, as disclosed for example in U.S. Pat. No. 6,690,029 or WO2005/055248 A1 or U.S. Pat. No. 7,385,221, are also useful.

Further preferred organic semiconducting materials are selected from thegroup consisting of small molecules or monomers of the tetra-heteroarylindacenodithiophene-based structural unit as disclosed in WO 2016/015804A1, and polymers or copolymers comprising one or more repeating unitsthereof, such as, for example, one of the following polymers (P-1) to(P-3):

Depending upon the intended application the present organicsemiconducting material may also comprise other components, such as, forexample, a fullerene or modified fullerene. In such blends of polymerand fullerene the ratio polymer:fullerene is preferably from 5:1 to 1:5by weight, more preferably from 1:1 to 1:3 by weight, most preferably1:1 to 1:2 by weight. Suitable fullerenes may, for example, beindene-C₆₀-fullerene bis-adduct like ICBA, or a (6,6)-phenyl-butyricacid methyl ester derivatized methano C₆₀ fullerene, also known as“PCBM-C₆₀” or “C₆₀PCBM”, as disclosed for example in G. Yu, J. Gao, J.C. Hummelen, F. Wudl, A. J. Heeger, Science 1995, Vol. 270, p. 1789 ffand having the structure shown below, or structural analogous compoundswith e.g. a C₆₁ fullerene group, a C₇₀ fullerene group, or a C₇₁fullerene group, or an organic polymer (see for example Coakley, K. M.and McGehee, M. D. Chem. Mater. 2004, 16, 4533).

Organic semiconducting materials may be purchased from commercialsources, such as SigmaAldrich or Merck KGaA (Darmstadt, Germany), or maybe synthesized according to published syntheses.

In a further aspect the present semiconducting material may be anoligomer or a polymer as defined above. Such oligomers and polymers maybe synthesized according to or in analogy to methods that are known tothe skilled person and are described in the literature from monomers asdescribed in the following.

Monomers that are suitable for the synthesis of the present oligomersand polymers may be selected from compounds comprising a structural unitof formula (I) and at least one reactive chemical group R^(C) which maybe selected from the group consisting of Cl, Br, I, O-tosylate,O-triflate, O-mesylate, O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹,—B(OZ²)₂, —CZ³═C(Z³)₂, —C≡CH, —C≡CSi(Z¹)₃, —ZnX⁰⁰ and —Sn(Z⁴)₃,preferably —B(OZ²)₂ or —Sn(Z⁴)₃, wherein X⁰⁰ is as defined herein, andZ¹, Z², Z³ and Z⁴ are selected from the group consisting of alkyl andaryl, preferably alkyl having from 1 to 10 carbon atoms, each beingoptionally substituted with R⁰ as defined herein, and two groups Z² mayalso together form a cyclic group. Alternatively such a monomer maycomprise two reactive chemical groups and is, for example, representedby formula (V-b)

R^(c)-M-R^(d)  (V-b)

wherein M is as defined herein and R^(C) and R^(d) are reactive chemicalgroups as defined above in respect to R^(C). Such monomers may generallybe prepared according to methods well known to the person skilled in theart.

X⁰⁰ is halogen. Preferably X⁰⁰ is selected from the group consisting ofF, Cl and Br. Most preferably X⁰⁰ is Br.

Preferred aryl-aryl coupling and polymerisation methods used in theprocesses described herein may, for example, be one or more of Yamamotocoupling, Kumada coupling, Negishi coupling, Suzuki coupling, Stillecoupling, Sonogashira coupling, Heck coupling, C—H activation coupling,Ullmann coupling and Buchwald coupling. Especially preferred are Suzukicoupling, Negishi coupling, Stille coupling and Yamamoto coupling.Suzuki coupling is described for example in WO 00/53656 A1. Negishicoupling is described for example in J. Chem. Soc., Chem. Commun., 1977,683-684. Yamamoto coupling is described for example in T. Yamamoto etal., Prog. Polym. Sci., 1993, 17, 1153-1205, or WO 2004/022626 A1, andStille coupling is described for example in Z. Bao et al., J. Am. Chem.Soc., 1995, 117, 12426-12435. For example, when using Yamamoto coupling,monomers having two reactive halide groups are preferably used. Whenusing Suzuki coupling, compounds of formula (I-b) having two reactiveboronic acid or boronic acid ester groups or two reactive halide groupsare preferably used. When using Stille coupling, monomers having tworeactive stannane groups or two reactive halide groups are preferablyused. When using Negishi coupling, monomers having two reactiveorganozinc groups or two reactive halide groups are preferably used.

Preferred catalysts, especially for Suzuki, Negishi or Stille coupling,are selected from Pd(0) complexes or Pd(II) salts. Preferred Pd(0)complexes are those bearing at least one phosphine ligand, for examplePd(Ph₃P)₄. Another preferred phosphine ligand istris(ortho-tolyl)phosphine, for example Pd(o-Tol₃P)₄. Preferred Pd(II)salts include palladium acetate, for example Pd(OAc)₂. Alternatively thePd(0) complex can be prepared by mixing a Pd(0) dibenzylideneacetonecomplex, for example tris(dibenzyl-ideneacetone)dipalladium(0),bis(dibenzylideneacetone)-palladium(0), or Pd(II) salts e.g. palladiumacetate, with a phosphine ligand, for example triphenylphosphine,tris(ortho-tolyl)phosphine or tri(tert-butyl)phosphine. Suzukipolymerisation is performed in the presence of a base, for examplesodium carbonate, potassium carbonate, lithium hydroxide, potassiumphosphate or an organic base such as tetraethylammonium carbonate ortetraethylammonium hydroxide. Yamamoto polymerisation employs a Ni(0)complex, for example bis(1,5-cyclooctadienyl)nickel(0).

Suzuki and Stille polymerisation may be used to prepare homopolymers aswell as statistical, alternating and block random copolymers.Statistical or block copolymers can be prepared for example from theabove monomers of formula (I-b), wherein one of the reactive groups ishalogen and the other reactive group is a boronic acid, boronic acidderivative group or and alkylstannane. The synthesis of statistical,alternating and block copolymers is described in detail for example inWO 03/048225 A2 or WO 2005/014688 A2.

As alternatives to halogens as described above, leaving groups offormula —O—SO₂Z¹ can be used wherein Z¹ is as described above.Particular examples of such leaving groups are tosylate, mesylate andtriflate.

Where appropriate and needed, for example, to modify the rheologicalproperties as is described for example in WO 2005/055248 A1, someembodiments of the present invention employ organic semiconductingcompositions that include one or more organic binders.

The binder, which is typically a polymer, may comprise either aninsulating binder or a semiconducting binder, or mixtures thereof, maybe referred to herein as the organic binder, the polymeric binder, orsimply the binder.

Preferred binders according to the present invention are materials oflow permittivity, that is, those having a permittivity ε of 3.3 or less.The organic binder preferably has a permittivity ε of 3.0 or less, morepreferably 2.9 or less. Preferably the organic binder has a permittivityε of 1.7 or more. It is especially preferred that the permittivity ofthe binder is in the range from 2.0 to 2.9. Whilst not wishing to bebound by any particular theory it is believed that the use of binderswith a permittivity ε of greater than 3.3, may lead to a reduction inthe OSC layer mobility in an electronic device, for example, in an OFET.In addition, high permittivity binders could also result in increasedcurrent hysteresis of the device, which is undesirable.

Examples of suitable organic binders include polystyrene, or polymers orcopolymers of styrene and α-methyl styrene; or copolymers includingstyrene, α-methylstyrene and butadiene may suitably be used. Furtherexamples of suitable binders are disclosed for example in US2007/0102696 A1.

In one type of preferred embodiment, the organic binder is one in whichat least 95%, more preferably at least 98% and especially all of theatoms consist of hydrogen, fluorine and carbon atoms.

The binder is preferably capable of forming a film, more preferably aflexible film.

The binder can also be selected from crosslinkable binders such asacrylates, epoxies, vinylethers, and thiolenes, preferably having asufficiently low permittivity, very preferably of 3.3 or less. Thebinder can also be mesogenic or liquid crystalline.

In another preferred embodiment the binder is a semiconducting binder,which contains conjugated bonds, especially conjugated double bondsand/or aromatic rings. Suitable and preferred binders are for examplepolytriarylamines as disclosed for example in U.S. Pat. No. 6,630,566.

The proportions of binder to OSC is typically 20:1 to 1:20 by weight,preferably 10:1 to 1:10 more preferably 5:1 to 1:5, still morepreferably 3:1 to 1:3 further preferably 2:1 to 1:2 and especially 1:1.Dilution of the compound of formula (V) in the binder has been found tohave little or no detrimental effect on the charge mobility, in contrastto what would have been expected from the prior art.

The present organic electronic device may optionally comprise one ormore substrates. Such substrate is not particularly limited and may beany suitable material that is inert under use conditions. Examples ofsuch materials are glass and polymeric materials. Preferred polymericmaterial include but are not limited to alkyd resins, allyl esters,benzocyclobutenes, butadiene-styrene, cellulose, cellulose acetate,epoxide, epoxy polymers, ethylene-chlorotrifluoro ethylene copolymers,ethylene-tetra-fluoroethylene copolymers, fiber glass enhanced polymers,fluorocarbon polymers, hexafluoropropylenevinylidene-fluoride copolymer,high density polyethylene, parylene, polyamide, polyimide, polyaramid,polydimethylsiloxane, polyethersulphone, polyethylene,polyethylenenaphthalate, polyethyleneterephthalate, polyketone,polymethylmethacrylate, polypropylene, polystyrene, polysulphone,polytetrafluoroethylene, polyurethanes, polyvinylchloride,polycycloolefin, silicone rubbers, and silicones. Of thesepolyethyleneterephthalate, polyimide, polycycloolefin andpolyethylenenaphthalate materials are more preferred. Additionally, forsome embodiments of the present invention the substrate can be anysuitable material, for example a polymeric material, metal or glassmaterial coated with one or more of the above listed materials or coatedwith one or more metal, such as for example titanium. It will beunderstood that in forming such a substrate, methods such as extruding,stretching, rubbing or photochemical techniques can be employed toprovide a homogeneous surface for device fabrication as well as toprovide pre-alignment of an organic semiconductor material in order toenhance carrier mobility therein. Alternatively, the substrate can be apolymeric material, metal or glass coated with one or more of the abovepolymeric materials.

A suitable substrate may, for example, be transparent orsemi-transparent. A suitable substrate may, for example, also beflexible or non-flexible.

Said substrate may, for example, serve as support and preferably beadjacent to a first electrode layer. Said substrate may, for example,also serve as support for the planarization layer holding the firstelectrode layer. In general, a substrate may be introduced into theelectronic device between or adjacent to any layer and placed such thatit serves best to support the device and/or be best placed with regardsto manufacturing requirements.

Additionally the present organic electronic device may optionallycomprise further layers acting as charge transport layers. Exemplarycharge transport layers may act as hole transporting layer and/orelectron blocking layer, or electron transporting layer and/or holeblocking layer. Generally—if present—such layers are between theelectrodes and the organic semiconducting layer.

Suitable materials for a hole transporting and/or electron blockinglayer may be selected from the group consisting of metal oxides, likefor example, zinc tin oxide (ZTO), MoOx, NiOx, a conjugated polymerelectrolyte, like for example PEDOT:PSS, a conjugated polymer, like forexample polytriarylamine (PTAA), an organic compound, like for exampleN,N′-diphenyl-N,N′-bis(I-naphthyl)(1,1′-biphenyl)-4,4′diamine (NPB),N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD).

Suitable materials for a hole blocking and/or electron transportinglayer may be selected from the group consisting of metal oxides, such asfor example, ZnOx, TiOx, a salt, like for example LiF, NaF, CsF, aconjugated polymer electrolyte, like for examplepoly[3-(6-trimethylammoniumhexyl)thiophene],poly(9,9-bis(2-ethylhexyl)-fluorene]-b-poly[3-(6-trimethylammoniumhexyl)thiophene],orpoly[(9,9-bis(3′-(N,N-dimethyl-amino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl-fluorene)]or an organic compound, like for exampletris(8-quinolinolato)-aluminium(III) (Alq₃),4,7-diphenyl-1,10-phenanthroline.

The present organic electronic device may, for example, be selected fromthe group consisting of organic field effect transistors (OFET), organicthin film transistors (OTFT), organic light emitting diodes (OLED),organic light emitting transistors (OLET), organic photovoltaic devices(OPV), organic photodetectors (OPD), organic solar cells, laser diodes,Schottky diodes, photoconductors and photodetectors. Preferably thepresent organic electronic device is an organic field effect transistor(PFET) or an organic thin film transistor (OTFT).

A preferred example of the present organic electronic device is anorganic field effect transistor, preferably comprising a gate electrode,a source electrode, a drain electrode, an insulating layer (preferably agate insulating layer), and an organic semiconducting layer. Optionallyan organic field effect transistor may also comprise one or moreselected from the group consisting of substrate and charge transportlayer. These layers in the OFET device may be arranged in any sequence,provided that the source electrode and the drain electrode are separatedfrom the gate electrode by the insulating layer, the gate electrode andthe semiconductor layer both contact the insulating layer, and thesource electrode and the drain electrode both contact the semiconductinglayer with the surface treatment layer in-between.

The OFET device according to the present invention can be a top gatedevice or a bottom gate device. Suitable structures of an OFET deviceare known to the skilled person and are described in the literature, forexample in US 2007/0102696 A1.

FIG. 1 shows a schematic representation of a typical top gate OFETaccording to the present invention, including source (S) and drain (D)electrodes (2) provided on a substrate (I), a self-assembled monolayer(3) formed by depositing a compound of formula (I) as defined hereinprovided on the S/D electrodes, a layer of organic semiconductingmaterial (4) provided on the S/D electrodes and the self-assembledmonolayer (3), a layer of dielectric material (5) as gate insulatorlayer provided on the organic semiconducting layer (4), a gate electrode(6) provided on the gate insulator layer (5), and an optionalpassivation or protection layer (7) provided on the gate electrode (6)to shield it from further layers or devices that may be provided lateror to protect it from environmental influence. The area between thesource and drain electrodes (2), indicated by the double arrow, is thechannel area.

FIG. 2 shows a schematic representation of a typical bottom gate-bottomcontact OFET according to the present invention, including a gateelectrode (6) provided on a substrate (I), a layer of dielectricmaterial (5) (gate insulator layer) provided on the gate electrode (4),source (S) and drain (D) electrodes (2) provided on the gate insulatorlayer (6), a self-assembled monolayer (3) formed by depositing acompound of formula (I) as defined herein provided on the S/Delectrodes, a layer of an organic semiconducting material (4) providedon the S/D electrodes and the self-assembled monolayer (3), and anoptional protection or passivation layer (7) provided on the organicsemiconducting layer (4) to shield it from further layers or devicesthat may be later provided or protect it from environmental influences.

In an OFET device according to the present invention, the dielectricmaterial for the gate insulator layer is preferably a solutionprocessable material. For the dielectric that is in direct contact withthe semiconductor. Especially preferred are organic dielectric materialshaving a dielectric constant from 1.0 to 5.0, very preferably from 1.8to 4.0 (“low k materials”), as disclosed for example in US 2007/0102696A1 or U.S. Pat. No. 7,095,044. For an optional second dielectric layerthe dielectric constant is not restricted, but preferably is fairly highin order to increase the device's capacitance.

Preferably the gate insulator layer is deposited, e.g. by spin-coating,doctor blading, wire bar coating, spray or dip coating or other knownmethods, from a formulation comprising an insulator material and one ormore solvents with one or more fluoro atoms (fluorosolvents), preferablya perfluorosolvent. A suitable perfluorosolvent is e.g. FC75® (availablefrom Acros, catalogue number 12380). Other suitable fluoropolymers andfluorosolvents are known in prior art, like for example theperfluoropolymers Teflon AF® 1600 or 2400 (from DuPont) or Fluoropel®(from Cytonix) or the perfluorosolvent FC 43® (Acros, No. 12377).Especially preferred are organic dielectric materials having adielectric constant from 1.0 to 5.0, very preferably from 1.8 to 4.0(“low k materials”), as disclosed for example in US 2007/0102696 A1 orU.S. Pat. No. 7,095,044.

The present transistor device may also be a complementary organic thinfilm transistor (CTFT) comprising a layer of a p-type semiconductormaterial as well as a layer of an n-type semiconductor material.

In general terms, the present application also relates to a method forproducing the present organic electronic device as described above, saidmethod comprising the steps of

-   (a) providing an electrode as defined herein, optionally on a    substrate as defined herein;-   (b) depositing onto said electrode a formulation comprising the    compound of formula (I) as defined herein and an alcohol of formula    R²—OH as defined herein to obtain the self-assembled monolayer; and-   (c) depositing onto said self-assembled monolayer an organic    semiconducting material to obtain an organic semiconducting layer.

In step (b), the formulation may, for example, be deposited onto theelectrode by vacuum or vapor deposition methods or by liquid coatingmethods. Exemplary deposition methods include physical vapor deposition(PVD), chemical vapor deposition (CVD), sublimation or liquid coatingmethods. Liquid coating methods are preferred. Particularly preferredare solvent-based liquid coating methods.

In solvent-based liquid coating a formulation, which comprises thecompound of formula (I) as defined herein and an alcohol of formulaR²—OH as defined herein (or the respective reaction product(s) of thecompound of formula (I) as defined herein and an alcohol of formulaR²—OH as defined herein), is deposited onto the metal surface or themetal oxide surface. Optionally, following deposition the solvent may beat least partially evaporated. Preferred solvent-based liquid coatingmethods include, without limitation, dip coating, spin coating, ink jetprinting, letter-press printing, screen printing, doctor blade coating,roller printing, reverse-roller printing, offset lithography printing,flexographic printing, gravure printing, web printing, spray coating,brush coating and pad printing.

In addition to the alcohol of formula R²—OH as defined herein, theformulation may comprise one or more further suitable solvent. Suchsuitable solvents may, for example, be selected from the groupconsisting of alcohols different from R²—OH as defined herein, ethers,ketones, aromatic hydrocarbons and any mixture of any of these. Suitableethers may have a linear or a cyclic structure and may for example beselected from the group consisting of diethylether, tetrahydrofuran(THF), butyl phenyl ether, methyl ethyl ether and 4-methylanisole.Suitable ketones may for example be selected from the group consistingof acetone, 2-heptanone and cyclohexanone. Suitable aromatichydrocarbons may for example be selected from the group consisting oftoluene, mesitylene, o-xylene, m-xylene, p-xylene, cyclohexylbenzene andhalogenated aromatic hydrocarbons. Examples of such halogenated aromatichydrocarbons are chlorobenzene, dichlorobenzene and trichlorobenzene aswell as any mixture of any of these.

Preferably the compound of formula (I) is present in (or expresseddifferently, is initially added to) the formulation or solution in from0.01 wt % to 10 wt %, preferably from 0.01 wt % to 5 wt %, and mostpreferably from 0.05 wt % to 2 wt %, with wt % being relative to thetotal weight of the formulation or solution.

The metal or metal oxide may be applied to the substrate by any of theconventional methods. The methods may for example be selected fromvacuum deposition, vapor deposition and liquid coating. Exemplarydeposition methods include physical vapor deposition (PVD), chemicalvapor deposition (CVD), sublimation or liquid coating methods. Suchmethods form part of the general knowledge in the field and are wellknown to the skilled person.

Before the SAM treatment, i.e. the formation of the self-assembledmonolayer, the metal or metal oxide surface is preferably subjected to awashing step. A preferred washing step comprises an acidic washing witha acid or a blend of acids, said acids being organic or inorganic acids.Examples of suitable acids are acetic acid, citric acid or hydrochloricacid. Alternatively the metal or metal oxide surface may be subjected toa plasma treatment step.

In a preferred embodiment, the washing step and the SAM treatment arecombined into a single step. For example, this combined step may becarried out by applying a formulation in accordance with the presentinvention to the metal or metal oxide surface, said formulationcomprising a precursor compound as defined above and an acid as definedabove.

Alternatively the washing step and the SAM treatment may be carried outsequentially in two separate steps.

The soaking time, i.e. the time during which the formulation is appliedto the metal or metal oxide surface, is preferably at least 5 s and atmost 72 h.

In the preparation of the other layers of the electronic devices,preferably the organic electronic devices, of the present inventionstandard methods may be used to deposit the various layers and materialsas described above.

Preferably the deposition of individual functional layers in thepreparation of the present electronic devices, such as for example theorganic semiconducting layer or the insulator layer, is carried outusing solution processing techniques. This can be done for example byapplying a formulation, preferably a solution, comprising the organicsemiconducting material or the dielectric material and furthercomprising one or more organic solvents, onto the previously depositedlayer, followed by evaporation of the solvent(s). Preferred depositiontechniques include, without limitation, dip coating, spin coating, inkjet printing, letter-press printing, screen printing, doctor bladecoating, roller printing, reverse-roller printing, offset lithographyprinting, flexographic printing, web printing, spray coating, brushcoating, or pad printing. Very preferred solution deposition techniquesare spin coating, flexographic printing and inkjet printing.

In an OFET device according to the present invention, the dielectricmaterial for the gate insulator layer is preferably an organic material.It is preferred that the dielectric layer is solution coated whichallows ambient processing, but could also be deposited by various vacuumdeposition techniques. When the dielectric is being patterned, it mayperform the function of interlayer insulation or act as gate insulatorfor an OFET. Preferred deposition techniques include, withoutlimitation, dip coating, spin coating, ink jet printing, letter-pressprinting, screen printing, doctor blade coating, roller printing,reverse-roller printing, offset lithography printing, flexographicprinting, web printing, spray coating, brush coating or pad printing.Ink-jet printing is particularly preferred as it allows high resolutionlayers and devices to be prepared. Optionally, the dielectric materialcould be cross-linked or cured to achieve better resistance to solventsand/or structural integrity and/or to improve patterning(photolithography). Preferred gate insulators are those that provide alow permittivity interface to the organic semiconductor.

Suitable solvents are selected from solvents including but not limitedto hydrocarbon solvents, aromatic solvents, cycloaliphatic cyclicethers, cyclic ethers, acetates, esters, lactones, ketones, amides,cyclic carbonates or multi-component mixtures of the above. Examples ofpreferred solvents include cyclohexanone, mesitylene, xylene,2-heptanone, toluene, tetrahydrofuran, MEK (methyl ethyl ketone), MAK(2-heptanone), cyclohexanone, 4-methylanisole, butyl-phenyl ether andcyclohexylbenzene, very preferably MAK, butyl phenyl ether orcyclohexylbenzene.

The total concentration of the respective functional material (organicsemiconducting material or gate dielectric material) in the formulationis preferably from 0.1 to 30 wt %, preferably from 0.1 to 5 wt %,relative to the total weight of the formulation (i.e. functionalmaterial(s) and solvent(s)). In particular organic ketone solvents witha high boiling point are advantageous for use in solutions for inkjetand flexographic printing.

When spin coating is used as deposition method, the OSC or dielectricmaterial is spun for example between 1000 and 2000 rpm for a period offor example 30 seconds to give a layer with a preferred layer thicknessbetween about 100 nm and about 2000 nm for the dielectric and about 5 nmto about 300 nm for the semiconductor. After spin coating, the film canbe heated at an elevated temperature to remove all residual volatilesolvents.

Optionally the dielectric material layer is annealed after exposure toradiation, for example at a temperature from 70° C. to 130° C., forexample for a period of from 1 to 30 minutes, preferably from 1 to 10minutes. The annealing step at elevated temperature can be used tocomplete the cross-linking reaction that was induced by the exposure ofthe cross-linkable groups of the dielectric material to photoradiation.

All process steps described above and below can be carried out usingknown techniques and standard equipment which are described in prior artand are well-known to the skilled person. For example, in thephotoirradiation step a commercially available UV lamp and photomask canbe used, and the annealing step can be carried out in an oven or on ahot plate.

Following the deposition of the self-assembled monolayer, preferably awashing step or a drying step or both are performed.

For the organic electronic device being a top gate OFET, following step(c), said process may additionally comprise the following steps,preferably in such sequence, of

-   (d) depositing as gate insulator layer a dielectric material as    defined herein onto the organic semiconducting layer;-   (e) depositing a gate electrode onto the gate insulator layer; and-   (f) optionally depositing a passivation layer onto the gate    electrode.

For the organic electronic device being a bottom gate OFET, before step(a), the process may further comprise the steps of

-   (o) depositing a gate electrode onto a substrate; and-   (o′) depositing as gate insulator layer a dielectric material onto    the gate electrode.

Optionally, following step (d), the process may further comprise thestep of

-   (d) depositing a passivation layer onto the organic semiconducting    layer.

Further layers may be deposited by standard methods, which are wellknown in the industry. Liquid coating of devices is more desirable thanvacuum deposition techniques. Solution deposition methods are especiallypreferred. Preferred deposition techniques include, without limitation,dip coating, spin coating, inkjet printing, nozzle printing,letter-press printing, screen printing, gravure printing, doctor bladecoating, roller printing, reverse-roller printing, offset lithographyprinting, dry offset lithography printing, flexographic printing, webprinting, spray coating, curtain coating, brush coating, slot dyecoating or pad printing.

Preferably the gate insulator layer is deposited, e.g. by spin-coating,doctor blading, wire bar coating, spray or dip coating or other knownmethods, from a formulation comprising an insulator material and one ormore solvents with one or more fluoro atoms (fluorosolvents), preferablya perfluorosolvent. A suitable perfluorosolvent is e.g. FC75® (availablefrom Acros, catalogue number 12380). Other suitable fluoropolymers andfluorosolvents are known in prior art, like for example theperfluoropolymers Teflon AF® 1600 or 2400 (from DuPont) or Fluoropel®(from Cytonix) or the perfluorosolvent FC 43® (Acros, No. 12377).

EXAMPLES

The advantages of the present application are illustrated by thefollowing non-limiting examples.

If not otherwise mentioned all solvents, salts, organic semiconductingmaterials etc. were obtained from commercial sources, such as forexample SigmaAldrich or Merck KGaA, Darmstadt, Germany.

It is noted that F₅C₆—SiCl₃ is sensitive to hydrolysis and therefore isbest stored in an environment free of humidity or residual water insolvents.

The electrical characterization of the transistor devices was carriedout in ambient air atmosphere using computer controlled Agilent 4155CSemiconductor Parameter Analyser. Charge carrier mobility in thesaturation regime (μ_(sat)) was calculated for the compound.Field-effect mobility was calculated in the saturation regime(V_(d)>(V_(g)−V₀)) using equation (eq. 1):

$\begin{matrix}{\left( \frac{dI_{d}^{sat}}{{dV}_{g}} \right)_{V_{d}} = {\frac{WC_{i}}{L}{\mu^{sat}\left( {V_{g} - V_{0}} \right)}}} & \left( {{eq}.\mspace{14mu} 1} \right)\end{matrix}$

where W is the channel width, L the channel length, C_(i) thecapacitance of insulating layer, V_(g) the gate voltage, V₀ the turn-onvoltage, and μ_(sat) is the charge carrier mobility in the saturationregime. Turn-on voltage (V₀) was determined as the onset of source-draincurrent.

Example 1—Work Function Measurement

Work functions were determined using a Kelvin Probe for electrodes withand without self-assembled monolayer (SAM), wherein the self-assembledmonolayer was prepared by immersing the respective electrodes on a glasssubstrate into a solution of F₅C₆—SiCl₃ in iso-propanol (^(i)Pr—OH),such solution thus—without wishing to be bound by theory—probablypredominantly comprising F₅C₆—Si(O-^(i)Pr)₃ as active species. Therespective results are indicated in Table 1.

TABLE 1 Work function Sample [eV] ITO without SAM 4.8 Molybdenum withoutSAM 4.9 ITO with SAM 5.4-5.6 (estimated) Molybdenum with SAM 5.5-5.7

Example 2—Device Preparation

Indium tin oxide (ITO) electrodes on glass were placed in a spin coaterand brought for one minute into contact with a solution of F₅C₆—SiCl₃ iniso-propanol (^(i)Pr—OH), such solution thus—without wishing to be boundby theory—probably predominantly comprising F₅C₆—Si(O—^(i)Pr)₃ as activespecies, thereby forming the self-assembled monolayer. Excess solutionwas spun off, following by rinsing with iso-propanol. Onto the resultingself-assembled monolayer was then deposited a layer of an organicsemiconducting material comprising derivatives of indacenodithiopheneand benzothiadiazole.

Respective mobilities are indicated in Table 2 below.

Example 3—Device Preparation (Comparative)

The preparation of Example 2 was repeated with the difference that forthe preparation of the self-assembled monolayer para-chlorobenzenephosphate (see formula (III) below) in iso-propanol, instead of theF₅C₆—SiCl₃ in iso-propanol, was used.

Respective mobilities are indicated in Table 2 below.

TABLE 2 Linear mobility Saturated mobility On off [cm²V⁻¹s⁻¹][cm²V⁻¹s⁻¹] ratio Example 2 1.06 1.72 10⁶ Example 3 (comp.) 0.38 0.5410⁶

1.-14. (canceled)
 15. An organic electronic device comprising anelectrode, a self-assembled monolayer on said electrode and an organicsemiconducting layer on said self-assembled monolayer, wherein saidself-assembled monolayer is formed by depositing the reaction product ofa compound of the following formula (IR¹—SiX₃  (I) and an alcohol of formula R²—OH onto said electrode, withR¹ being at each occurrence independently alkyl having from 1 to 10carbon atoms, said alkyl being substituted with at least oneelectron-withdrawing group R^(A), or aryl having from 6 to 30 aromaticcarbon ring atoms, said aryl being substituted with at least oneelectron-withdrawing group; R² being an alkyl group having from 1 to 10carbon atoms; and X being at each occurrence independently halogen oralkoxy having from 1 to 10 carbon atoms.
 16. The organic electronicdevice according to claim 15, wherein the self-assembled monolayer isformed by depositing the formulation comprising the compound of formula(I) and the alcohol of formula R²—OH onto the electrode.
 17. The organicelectronic device according to claim 15, wherein R¹ is at eachoccurrence independently a group select of any of the following formulae(II-a) or (II-b)

wherein b is at each occurrence independently an integer of at least 1and of at most 10; c is at each occurrence an integer of at least 1 andat most 2b+1; d is at each occurrence an integer of at least 0 and atmost 2b; with the provision that the sum of c and d is 2b+1; and e is ateach occurrence independently an integer of at least 1 and of at most 5.18. The organic electronic device according to claim 17, wherein c is2b+1.
 19. The organic electronic device according to claim 17, wherein eis
 5. 20. The organic electronic device according to claim 15, whereinR^(A) is at each occurrence independently selected from the groupconsisting of —NO₂, —CN, —F, —Cl, —Br, —I, —OAr², —OR³, —COR³, —SH,—SR³, —OH, —C≡CR³, —CH═CR³ ₂, and alkyl having from 1 to 10 carbonatoms, wherein one or more, preferably all, hydrogen atoms are replacedby F, with Ar² being at each occurrence independently an aryl havingfrom 6 to 30 carbon atoms, and R³ being at each occurrence independentlyan alkyl having from 1 to 10 carbon atoms or an alkyl having from 1 to10 carbon atoms wherein one or more hydrogen atom is replaced by F. 21.The organic electronic device according to claim 15, wherein R^(A) is F.22. The organic electronic device according to claim 15, wherein thecompound of formula (I) is selected from the group consisting of thefollowing formulae (I-1) to (I-11)

wherein e is an integer of at least 1 and at most
 10. 23. The organicelectronic device according to claim 15, wherein the electrode is anindium tin oxide electrode.
 24. The organic electronic device accordingto claim 15, wherein R² is an alkyl having from 1 to 5 carbon atoms. 25.The organic electronic device according to claim 15, wherein R² isiso-propyl.
 26. The organic electronic device according to claim 15,said organic electronic device being selected from the group consistingof organic field effect transistors (OFET), organic thin filmtransistors (OTFT), organic light emitting diodes (OLED), organic lightemitting transistors (OLET), organic photovoltaic devices (OPV), organicphotodetectors (OPD), organic solar cells, laser diodes, Schottkydiodes, photoconductors and photodetectors.
 27. The organic electronicdevice according to claim 15, said organic electronic device being anorganic field effect transistor (PFET) or an organic thin filmtransistor (OTFT).
 28. A method of producing the organic electronicdevice of claim 15, said method comprising the steps of (a) providing anelectrode, optionally on a substrate; (b) depositing onto said electrodea formulation comprising a compound of formula (I)R¹—SiX₃  (I) and an alcohol of formula R²—OH, with R¹ being at eachoccurrence independently alkyl having from 1 to 10 carbon atoms, saidalkyl being substituted with at least one electron-withdrawing groupR^(A), or aryl having from 6 to 30 aromatic carbon ring atoms, said arylbeing substituted with at least one electron-withdrawing group R^(A); R²being an alkyl group having from 1 to 10 carbon atoms; and X being ateach occurrence independently halogen or alkoxy having from 1 to 10carbon atoms, to obtain a self-assembled monolayer; and (c) depositingonto said self-assembled monolayer an organic semiconducting material toobtain an organic semiconducting layer.
 29. The method according toclaim 28, wherein R¹ is at each occurrence independently a group selectof any of the following formulae (II-a) or (II-b)

wherein b is at each occurrence independently an integer of at least 1and of at most 10; c is at each occurrence an integer of at least 1 andat most 2b+1; d is at each occurrence an integer of at least 0 and atmost 2b; with the provision that the sum of c and d is 2b+1; and e is ateach occurrence independently an integer of at least 1 and of at most 5;wherein R² in the alcohol R²—OH is an alkyl having from 1 to 5 carbonatoms; and the electrode is an indium tin oxide electrode.